The Round Top plate. Relief from Copernicus GLO-30; rivers and lakes from USGS NHD; watersheds from the USGS Watershed Boundary Dataset; roads and city limits from Census TIGER 2024.
Chance of showers
Showers likely
Chance of showers
Mostly sunny; warmer
Mostly cloudy
Partly cloudy
Partly cloudy
97° on Nov. 15, 2025, the hottest reading for this week of the year since 1897. Next is 94° in 1927.
Round Top’s center stands about 440 ft above sea level. Within three miles the land runs from 330 ft to 480 ft, a difference of 150 ft: gently rolling country.
Under the town center the state geologic map shows Oakville Sandstone (sandstone, clay), from the Miocene, 5.3 to 23 million years old.
The section below crosses 5 rock units mapped at the surface.
Heights every 0.1 mile from the Copernicus GLO-90 surface model; vertical exaggeration about 64×. The colored band under the surface is the rock the state geologic map shows at the surface, not a picture of what lies beneath.
Sandstone, clay. Age: Miocene, 5.3 to 23 million years old. About 18 mi of the line.
Mudstone, sand. Age: Oligocene, 23 to 34 million years old. About 5 mi of the line.
Coarse-detrital, fine-detrital. Age: Pliocene, 2.6 to 5.3 million years old. About 0.8 mi of the line.
Sand. Age: Pleistocene to Holocene, less than 2.6 million years old. About 0.5 mi of the line.
Fine-detrital, coarse-detrital. Age: Holocene, less than 12,000 years old. About 0.4 mi of the line.
From the USGS State Geologic Map Compilation (Horton and others, 2017), the states’ geologic maps joined at a common scale.
Heights from Copernicus GLO-90 (a surface model: it includes buildings and tree canopy); summits from USGS GNIS; rivers from USGS NHDPlus HR; rock from the USGS State Geologic Map Compilation.
A raindrop that lands in Round Top reaches the Gulf of America by way of Cummins Creek and the Colorado: about 170 river miles.
130 miles of the trip are on the Colorado.
Traced down the USGS NHDPlus V2.1 river network from the Census center point of Round Top; river miles along the main stem, rounded.
Round Top has a humid subtropical climate. Summer afternoons average 95° in August; winter nights fall to about 39° in January. About 48 inches of rain fall in a normal year.
On November 14 Round Top normally reaches 70° and falls to 48°. The record high is 91°, in 1921; the record low 26°, in 1940. The most rain on this date, 1.35 in, fell in 1920.
Normals 1991–2020 and records since 1897 at Brenham, 19 miles east-northeast, 130 ft lower. NOAA, through RCC-ACIS.
